The Cable Operators (MSOs) have complete control of what cable modem/gateway hardware they will allow installed and the firmware it uses, this is because they own the coaxial cable that is connected to the ARRIS (G36), because of that the Firmware updates are pushed by them, and any update needed as well. Any associated firmware updates are automatically deployed by the cable operator. This is not an ARRIS only implementation, but the required implementation of any cable device manufacturer.

Even for the device owned by the customer only service provider can send updated to the modem when its required from their end. customer or the manufacturer cannot manually update the firmware.

Arris needs to make an acceptable firmware upgrade that the MSOs can verify before pushing out to their customers.

Xfinity and Cox have determined 01.05 is not a suitable firmware version to push, so Arris needs to address the concerns with 01.05, and make a new revision for verification.

The G36 is unfortunately a lemon at this stage because it has no stable firmware version for it. I own one too (with Xfinity) and it's the same old song and dance.

ARRIS develops the software update and makes it available to service providers.  The service providers qualify, test, and distribute the software update to devices on their network.  ARRIS has limited control or visibility over distribution by the service providers.